An effective oral composition can maintain and preserve tooth appearance by removing dental stains and polishing the teeth. It may clean and remove external debris as well, which can aid the prevention of tooth decay and promote gingival health.
Abrasives in oral compositions aid in the removal of the tightly adherent pellicle film to which dental stains affix. Pellicle film usually comprises a thin acellular, glycoprotein-mucoprotein coating, which adheres to the enamel within minutes after teeth are cleaned. The presence of various food pigments lodged within the film accounts for most instances of teeth discoloration. An abrasive may remove the pellicle film with minimal abrasive damage to oral tissue, such as the dentin and enamel.
In addition to cleaning, it may be desirable for abrasive systems to provide polishing of tooth surfaces, as polished surfaces may be more resistant to ectopic deposition of undesirable components. Tooth appearance may be improved by imparting a polished character to the teeth, because the surface roughness, that is, its polish, affects light reflectance and scattering, which integrally relate to the teeth's visual appearance. The surface roughness also affects tooth feel. For example, polished teeth have a clean, smooth, and slick feel.
It is also desirable for oral compositions to offer actives that can address particular consumer needs, such as hypersensitivity. Dentin hypersensitivity is characterized by brief, sharp pain, and is closely related to exposed dentinal tubules. It is believed that blockage of exposed dentinal tubules is one way to lessen dentin hypersensitivity, but dentinal tubules are generally smaller than the particle size of typically used abrasives.